Geo-engineering wins scant enthusiasm at UN climate talks

DOHA, Dec 2 Cheap, short-cut ideas to cool the
planet such as shading sunlight are failing to win support from
U.N. delegates looking to improve on the slow progress made by
existing technologies.

Many scientists say the proposed solutions, known as
geo-engineering, are little understood and might have side
effects more damaging than global warming, which is projected to
cause more floods, heatwaves, droughts and rising sea levels.

"Let's first use what we know," said Christiana Figueres,
head of the U.N. Climate Change Secretariat, dismissing
suggestions that it was time to try geo-engineering to halt a
rise in greenhouse gas emissions.

"There are so many proven technologies we know exist that
are tried and true that have not been used to their maximum
potential," she told Reuters. "To begin with, the simplest is
energy efficiency."

Geo-engineering options include adding sun-reflecting
chemicals to the upper atmosphere to mimic the effect of big
volcanic eruptions that mask the sun, or fertilising the oceans
to promote the growth of algae that soak up carbon from the air.

Among other ideas, a giant mirror could be placed in space
to block some sunlight or sea spray could be injected into the
air to create clouds whose white tops would reflect sunlight.

"Let's face it, geo-engineering has a lot of unknowns,"
Rajendra Pachauri, chairman of the U.N.'s panel of climate
scientists, told Reuters on the sidelines of U.N.-led climate
change talks among 200 nations in Doha from Nov. 26-Dec 7.

"How can you go into an area where you don't know
anything?" he said. The Intergovernmental Panel on Climate
Change (IPCC) is examining geo-engineering in depth for the
first time as part of a major report due in 2013 and 2014.

Still, one study by U.S. scientists in August indicated
that planes or airships could carry a million tonnes a year of
sun-dimming sulphate materials high into the atmosphere for an
affordable price tag of below $5 billion.

CHEAPER

That would be far cheaper than policies to cut world
greenhouse gas emissions, estimated to cost between $200 billion
and $2 trillion a year by 2030, they wrote in the journal
Environmental Research Letters.

"If you are looking at solutions you could look at solar
energy," said Mira Mehrishi, head of India's delegation in Doha.
"It's a little premature to start looking at geo-engineering."

"There's a lot of scepticism" about geo-engineering, said
Artur Runge-Metzger of the European Commission. "Research is
necessary to see if it could be viable in one way or other."

U.N. negotiations on slowing global warming have been
running since a U.N. Climate Convention was agreed in 1992.

One problem is that adding sulphates - a form of pollution -
to the air would not slow an acidification of the oceans since
concentrations of greenhouse gases led by carbon dioxide in the
atmosphere would keep building up.

Some carbon dioxide, absorbed into the oceans, reacts to
form carbonic acid. That erodes the ability of creatures from
clams or mussels to lobsters and crabs to build their protective
shells. In turn, that could disrupt marine food chains.

"You might temporarily delay the warming but you are
certainly not going to help the oceans at all," said Jean-Pascal
van Ypersele, a vice-chair of the IPCC, of using sulphates.
"Ocean acidification is a real emerging issue."

A mask of pollution might help some crops by reducing heat
stress but it might have other side-effects, for instance, by
disrupting Monsoon patterns. That could bring disputes between
countries that benefited and others that suffered.

And Van Ypersele said that, if geo-engineering went wrong
and needed to be shut down after a few years, there would be a
big, damaging jump in temperatures.

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